I bought my 2012 August 17th, and as of December 28th, I have roughly 9500 miles on her. So yeah....she sees the road, not the garage walls!
I have a great crew at a local hand-wash place that runs me about 30 bucks bi-weekly and they do the exterior only. Between those two-week periods I spot clean, spray wax and detail the interior.
Come spring, I'll strip and hand wax myself twice a year or so.
...and I vacuume whenever needed with my new eureka 71b hand held
After all is said and done, I'd hate to try and consider the actual cost.